RodneyS

For those of us of a certain age, the answer to the question of "your most memorable snowstorm" is a no-brainer. Nothing comes close to this one because it was so unexpected, as detailed here: How the surprise President’s Day snowstorm of 1979 advanced forecasting - The Washington Post. When I went to bed on the evening of Sunday, February 18, 1979 (February had the same calendar that year as in 2024), I expected to wake up to a coating of 2-3 inches. Instead, when I woke up on Presidents' Day, I literally could not see my car! What was equally extraordinary is that people in the Reston neighborhood where I lived came out en masse that morning to take it all in, and everyone was in an upbeat mood. No one could quite believe that we had received that much snow (officially 18.7 inches at Reagan National Airport -- the most in DC since the January 27-29, 1922 Knickerbocker Storm), when little had been forecast. Since then, there have been larger storms in the Maryland and Virginia suburbs, but none compare to this one for emotional impact.

This Presidents Day weekend storm did not quite live up to billing, but did produce 2.2 inches at BWI, 0.1 at DCA, and 1.1 at IAD. That enabled RickinBaltimore to move into second place behind Kmlwx. A very competitive leaderboard, but will the Mid-Atlantic receive any more snow this season?

Somewhere along the way, IAD's snow total for January was revised upward by 0.2 inches, and today IAD added another 0.6 inches. Those changes move SnowDreamer and RickinBaltimore into stronger contention, while eliminating me. Kmlwx and GramaxRefugee are still the Top Two and both benefited from no measurable snow today at BWI and DCA.

The precipitation slowed at DCA over the past three weeks, but still managed an additional 2.62 inches, to bring January precipitation there to 5.88 inches, good enough for the 7th-most in DC history. Moreover, the December-January total is now 12.31 inches, which is the most to start a meteorological winter in 87 years. That December 1936-January 1937 produced 13.06 inches in DC, and the only December-January to exceed that was way back in 1881-82, which recorded 13.21 inches.

DCA _ NYC _ BOS __ ORD _ ATL _ IAH __ DEN _ PHX _ SEA 0.3 1.9 1.0 3.5 0.0 1.8 0.8 -1.3 -0.2

I have updated the list to add the lowest and second lowest temperatures of each month in DC. Note how -- while record high temperatures have occurred more frequently in recent years -- they encompass essentially the entire period of record (1872-2024). On the other hand, with a few exceptions, record low temperatures occurred almost entirely in the old days. January: Highest -- 26th of 2024 (80); second highest -- 26th of 1950 (79) January: Lowest -- 1st of 1881 (-14); second lowest -- 14th of 1912 (-13) February: Highest -- 25th of 1930 (84); second highest -- (tie) 21st of 2018 and 28th of 1948 (82) February: Lowest -- 11th of 1899 (-15); second lowest -- 10th of 1899 (-8) March: Highest -- 23rd of 1907 (93); second highest -- 29th of 1907 (92) March: Lowest -- 4th of 1873 (4); second lowest -- 5th of 1872 (5) April: Highest -- (tie) 17th of 2002, 18th of 1976, 23rd of 1960, and 27th of 1915 (95) April: Lowest -- 1st of 1923 (15); second lowest -- 19th of 1912 (22) May: Highest -- 31st of 1991 (99); second highest -- 30th of 1991 (98) May: Lowest -- 11th of 1906 (33); second lowest -- (tie) 9th of 1947 and 1st of 1876 (34) June: Highest -- 29th of 2012 (104); second highest -- (tie) 9th of 2011 and 9th of 1874 (102) June: Lowest -- 2nd of 1897 (43); second lowest -- (tie) 1st of 1938, 1st of 1930, 11th of 1913, 9th of 1913, 9th of 1912, 3rd of 1910, 9th of 1891 (45) July: Highest -- 20th of 1930 (106); second highest -- (tie) 7th of 2012 and 10th of 1936 (105) July: Lowest -- (tie) 4th of 1933, 4th of 1907, 31st of 1895 (52) August: Highest -- 6th of 1918 (106); second highest -- 17th of 1997 (105) August: Lowest -- (tie) 29th of 1986, 31st of 1934, and 24th of 1890 (49) September: Highest -- 7th of 1881 (104); second highest -- 2nd of 1980 (101) September: Lowest -- 23rd of 1904 (36); second lowest -- (tie) 30th of 1912 and 26th of 1879 (38) October: Highest -- 2nd of 2018 (98); second highest -- 5th of 1941 (96) October: Lowest -- (tie) 31st of 1917, 31st of 1893, 30th of 1873 (26) November: Highest -- 1st of 1974 (86); second highest -- 2nd of 1971 (85) November: Lowest -- 30th of 1929 (11); second lowest -- (tie) 23rd of 1880 and 22nd of 1880 (12) December: Highest -- 7th of 1998 (79); second highest -- 6th of 1998 (78) December: Lowest -- 31st of 1880 (-13); second lowest -- 30th of 1880 (-7)

My research indicates that January is the only month in DC history where the two highest temperatures of a month have fallen on the same day. Here is the complete list: January: Highest -- 26th of 2024 (80); second highest -- 26th of 1950 (79) February: Highest -- 25th of 1930 (84); second highest (tie) -- 21st of 2018 and 28th of 1948 (82) March: Highest -- 23rd of 1907 (93); second highest -- 29th of 1907 (92) April: Highest -- (tie) 17th of 2002, 18th of 1976, 23rd of 1960, and 27th of 1915 (95) May: Highest -- 31st of 1991 (99); second highest -- 30th of 1991 (98) June: Highest -- 29th of 2012 (104); second highest (tie) -- 9th of 2011 and 9th of 1874 (102) July: Highest -- 20th of 1930 (106); second highest (tie) -- 7th of 2012 and 10th of 1936 (105) August: Highest -- 6th of 1918 (106); second highest -- 17th of 1997 (105) September: Highest -- 7th of 1881 (104); second highest -- 2nd of 1980 (101) October: Highest -- 2nd of 2018 (98); second highest -- 5th of 1941 (96) November: Highest -- 1st of 1974 (86); second highest -- 2nd of 1971 (85) December: Highest -- 7th of 1998 (79); second highest -- 6th of 1998 (78)

Today, January 26, 2024, Reagan National Airport shattered the DC record for the earliest 80-degree reading of the year by 26 days. DCA reached exactly 80 today, and the previous record-holder was February 21st (2018), which reached 82. Similarly, while Dulles International Airport fell a degree short of 80 today, it shattered the IAD record for the earliest 79-degree reading of the year by 26 days. Again, the previous record-holder was February 21, 2018, which reached 80 at IAD.

When I initiated this thread 11 years ago today, I wrote, regarding officially-reported DC temperatures for two days in January: "January 13th has gone from being the coldest January day at 33.3 degrees on average during 1872-1983 to the warmest January day at 40.3 degrees on average during 1984-2013 -- an increase of 7.0 degrees. January 21st has been the mirror image of January 13th -- going from the second warmest January day at 36.8 degrees on average during 1872-1983 to the coldest day of the year at 32.1 degrees on average during 1984-2013 -- a decrease of 4.7 degrees." So what has happened during the last 11 years? Essentially, a repeat of 1984-2013, but with slightly warmer temperatures for the two days. January 13th this year at DCA averaged 44.5 degrees, to bring the 2014-2024 average for that day to 41.5 -- 1.2 degrees warmer than 1984-2013. January 21st this year at DCA averaged 27.5 degrees, to bring the 2014-2024 average for that day to 33.6 -- 1.5 degrees warmer than 1984-2013. Thus, instead of January 13th and January 21st temperatures at DCA each regressing to the mean January 13-21 temperature over the past 11 years, which would be likely if the prior 30 years had been a statistical aberration, January 13th has continued to be abnormally warm, while January 21st has continued to be abnormally cold. That suggests that this "thaw-freeze" situation in DC is caused by a repeating weather phenomenon, likely relating to warming temperatures worldwide. But what is the specific mechanism that is responsible for this phenomenon?

Yesterday's snow totals at the three Baltimore-Washington airports have all been revised upward; see updated spreadsheet below.

It is certainly not what I envisioned, but during the 2006-07 (Weak El Nino) winter season, the final snow totals were: BWI 11.0, DCA 9.5, IAD 14.7, RIC 1.3.

Your reign was awesome, but like Pope John Paul I, all too brief. Here is the updated spreadsheet:

You were one year too late at AccuWeather to have helped forecast the Presidents Day Storm of 1979, which occurred in the Mid-Atlantic on February 18-19. However, I recall that AccuWeather did a much better job of forecasting that storm than did the National Weather Service. If you have any old AccuWeather contacts left, you might want to ask them about that storm. The following article, written by two members of the Capital Weather Gang, notes the failure of the National Weather Service to even come close on that forecast: How the surprise President’s Day snowstorm of 1979 advanced forecasting - The Washington Post

I dunno, Roger, AccuWeather's long-range forecast calls for sunny skies in DC on those two days, and when has that forecast ever been wrong? https://www.accuweather.com/en/us/washington/20006/daily-weather-forecast/327659?day=21

Your two closest competitors can't catch you, and so if we get no more than an inch at each of the airports on Friday, you will remain in the lead.

We indeed have a new leader -- previous Mid-Atlantic snow contest operator @PrinceFrederickWx. So far, the reports for this storm are as follows: BWI 4.9 inches DCA 4.1 inches IAD 4.4 inches RIC 0.5 inches There still may be updates to these figures, but the table below shows the current standings.

I see that as of 1 PM today (Monday, MLK day), DCA is reporting 0.7 inches and IAD is reporting 0.9 inches. By tomorrow morning, we should have a new leader -- something that did not happen last season ;-). I will update the leader board on Tuesday.

Interesting note from the Capital Weather Gang: "The 2.24 inches at Reagan National Airport, 1.76 inches at Dulles International Airport, and 2.62 inches at Baltimore-Washington International Marshall Airport were all record amounts for the date. That brings Washington’s total rainfall to 9.69 inches since Dec. 1, well past the previous high of 7.56 inches during the same period in 1901-1902, according to Capital Weather Gang’s Ian Livingston." See https://www.washingtonpost.com/weather/2024/01/10/dc-storm-flooding-record-rainfall

DCA _ NYC _ BOS __ ORD _ ATL _ IAH __ DEN _ PHX _ SEA -0.2 1.0 1.6 1.3 -1.7 -0.5 -3.1 -1.0 -1.6

2023 gave it a good try, but could not quite catch 2012 for the warmest calendar year ever in DC. December 2023 at DCA finished at 45.5 degrees, tied for the 5th warmest December in DC history. However, that brought the yearly average only to 61.3 degrees, vs 61.6 in 2012. 2023 did displace 2017 (60.8) as the 2nd warmest in DC history.

Based on the numbers from the Capital Weather Gang, RIC Airport, and yoda, below is the updated spreadsheet. EastCoast NPZ is still in the lead, but he does have an unwanted distinction that no one achieved last season: Negative departures at DCA, IAD, and RIC.

Thanks. So RIC and IAD (0.5 inches) have exceeded last season's snow totals. I have not yet heard about measurable snow at BWI or DCA. I will update the spreadsheet when I do.

Thanks, Herb. I know that the Capital Weather Gang had one of their better snow forecasts for 2009-10, but I'm not sure anyone foresaw the record amount of snow that season.

Thanks, Roger. I wonder if anyone ran a Mid-Atlantic contest on any Internet site in 2009-10? If so, were the picks abnormally high?

Are you already regretting not following through on your below statement of November 10th? Just waiting til the last possible minute to go .1 across the board…